1. Technical Field
The present invention relates to systems, apparatus, and methods to contain and remove oil from a body of water. It can also apply to any immiscible liquids in which the lighter liquid is extracted from the heavier.
2. Description of Related Art
U.S. Pat. No. 3,959,136 to Ayers et al. discloses a method and apparatus for removing small volumes of oil from the surface of a body of water. The device in Ayers skims the surface as it is moved through the water by boat.
U.S. Pat. No. 4,449,850 to Cessou et al. discloses an inverted conical funnel for trapping oil as it comes out of a broken well. The device in Cessou is designed to cap the well and remove the oil at the source of the spill.
U.S. Pat. No. 7,410,577 to Broje et al. discloses an apparatus for recovering surface oil from a spill by using a skimmer with a grooved spinning drum. The grooves improve the adherence of oil to the drum while spinning off the water.
3. Causes of Failure
Rapid response to properly clean up an oil spill is critical. The fast spread of oil on water makes containing it harder by the minute. The oil's increased surface area also speeds its evaporation, leaving the remaining oil more viscous, sticky, heavy and difficult to clean up. If not removed before reaching a “tar ball” stage, large scale cleanup becomes nearly impossible. As tar balls sink almost below the surface, evaporation no longer occurs on the surface of the ball, and they remain suspended in the water column until they wash ashore.
One cause of delay is the lack of local cleanup equipment. Current equipment is expensive, bulky, and too infrequently used for most outfitters and boat owners to invest in it. Strong ultra-light materials now allow the manufacture of portable and relatively inexpensive equipment in kit form. Other causes of delay are how to recruit enough local volunteer boats to effect the cleanup, who will pay them, and how would they get the necessary booms to contain the spill.
While corralling an oil slick, it can become so thick that oil escapes under the boom. Therefore if the speed of harvesting does not match or exceed the speed of concentration of the oil, the ability to recover the oil is lost and it pollutes the water and shore. There is need for equipment and techniques that permit recovery of oil from water at a sufficiently high rate.